Metal cutting apparatus



Dec. 31, 1940. c. a. GRAY METAL CUTTING APPARATUS 2 Sheets-Shah's 1Filed umh 20. 193'! Jhdentor CHARLES B. GRAY Dec. 31,, 1940; c. B; GIRAYI 2,227,031v

METAL CUTTING APPA RATUS v Filed March 20, 1937 V 2 Sheet-Sheet 2'InUenZb r v CHARLES BJ R Y i j v Patented Dec. 31, 1940 UNITED STATESazzwn PATENT, oFFice METAL CUTTING APPARATUS Charles B. Gray,Millbourne, Pa.

Application March 20, 1937, Serial No. 132,010

18 Claims. (01. 164- 17 This invention relates to machines for cuttingor slotting sheet or plate material and more particularly to an improvedconstruction of machines known in the art as nibbling machines, one formof which is shown in my prior Patent No. 1,849,829,

granted March 15, 1932. In these nibbling machines, a punch and pilotmember are employed in such manner that they cooperate to slot a sheetor plate material fed through the machine, the pilot member serving tolimit the increment of feed. The punch and pilot member of the presentmachine are in the form of a unitary member which is carried by avertically reciprocable ram, the latter being also rotatable about itsvertical or longitudinal axis so as to present the cutting edge of thepunch in position to permit cutting or nibbling of the stock in anydesired direction.

It is among the objects of the present invention 20 to provide in anibbling machine of the character just stated a supporting structure forthe ram which not only permits vertical reciprocation and rotatableadjustment of the ram along and about its axis but also provides abearing for the ram which is practically coextensive in lengththerewith, thereby afiording greater bracing for the ram against lateraldeflection than has been afforded heretofore.

Still another important object is to provide an arrangement wherein theram is vertically reciprocable within a bushing rotatably mounted withina fixed guide bearing formed as a part of the machine in consequence ofwhich a greater vertical support is provided for the ram during itsreciprocatory movement, thereby reducing to a minimum the length of theram which is unsupported against possibility of lateral deflection dueto eccentrically applied loads, at the same time providing for rotationof the ram about its vertical 40 axis to permit presentation of thecutting edge of the tool in any desired direction.

A still further object of the invention is to provide an improvedconstruction of tool holder of such character that the tool is supportedagainst buckling throughout substantially the entire length thereof andin which provision is had for adjusting the tool axially of the ram andthe tool support to compensate for decreased tool length occasioned byredressing dull or broken tools.

A still further object is to providea tool assembly having means forfacilitating the insertion and removal of the tool in and from the ramand for insuring accurate axial alinement of the tool and ram so thatwhen the tool is firmly secured within its holder there is nopossibility of the tool having any cooking or twisting tendency such aswould result in eccentric motion when the tool wasrotated, it beingnoted in this connection thatin the machine of the present invention thedie with which the toolcooperates to nibblef the stock is stationary, inconsequence of which it is absolutely necessary, in order to save boththe tool and die from premature wear and probable total destruction,that the tool be constantly in axial alinement with the die regardlessof the angular adjustment 10 of the tool about its axis. Still anotherand important object of the present invention is to provide a toolassembly embodying a vertically reciprocable ram and an adjustablyassociated tool together with means ,15 for relating the tool axially ofthe ram so that regardless of the overall length of the tool apredeterminedly fixed relation is always obtainable between the tool andits associated fixed die, said means being so operative that in everypositional 0 adjustment of the tool axially of the ram it is supportedin its entirety against buckling or lateral defection at the same timethat it is also supported against any axial displacement rela tively tothe ram during both working and back ,25 strokes thereof. it

Other objects and advantagesof the invention will be apparent more fullyhereinafter, it being understood that the present invention consistssubstantially in the combination, construction, 0 location and relativearrangement of parts, all as will be described more fully hereinafter,as

shown in the accompanying drawings and as finally pointed out in theappended claims. In the said accompanying drawings, which are in- 3tended to be illustrative of the principles of the present invention: iv

Figure 1 is a front elevational view of the machine constructed inaccordance with and embodying the principles of the present invention;40

Figure 2 is a side view thereof with the operating parts thereof shownin vertical cross-section;

Figure 3 is an enlarged vertical cross-sectional view of the ram andtool assembly and the parts of the machine immediately associatedtherewith;

Figure 4 is a horizontal sectional view taken 0 the line tl4i of Figure2; c I

Figure 5 is a horizontal sectional View taken on theline 5-5 of Figure2; and

Figure 6 is a vertical cross-sectional view of a j 50 modifiedconstruction of the ram andtool holder assembly. 1

Referring now more particularly to the drawings, it will be observedthat the nibbling machine of the present invention includes a frame Ithay- 5 ing an upper jaw H and a lower jaw H2. The upper jaw carries adriving member I? connected by a connectible coupling 14 interposedbetween the shafts l5 and 16 to an eccentric i? for converting rotarymotion of the" driving member into reciprocatory motion. of the slide itto which a suitable tool may be connected. The lower jaw I 2 is providedwith means for receiving and holding firmly in adjusted position asuitable fixed die or block [8.

Operatively associated with the sliding head N5 of the machine is a ram19, suitable mechanism being interposed between said sliding head andram for effecting the desired reciprocatoryoperation of the ram. Thismechanism includes a gag mechanism, designated generally by thereference numeral 28, which permits of readyretraction of the tool fromthe workby means and for the purpose more particularly described in theLetters Patent No. 1,849,829, granted March 15, 1932, referred tohereinabove. Inasmuch as the gag mechanism in the present machine is ofthe patent.

ram l9 may be vertically adjusted as desired, a

nut lock 23 being provided to maintain the rain in its adjustedposition.

The upper jaw ll of the machine is provided 'in its extremity withavertically extending bore 24 of substantial axial dimension. Disposedinteriorly of thisbore for rotation therewithin is a sleeve 25, theupper end of which isprovided with a radially extending flange 26overlying the upper surface of the jaw l I immediately surrounding thevertical bore 24 thereof. The rotatable sleeve '25 is provided with aninternally tapered bore 27 within which is fitted a 'complementalexternally tapered bushing 28, the internal bore of this bushing beingof cylindrical surface and of a diameter .to snugly accommodate forreciprocatory motion therein the ram Hi. It willbe observed that thesleeve and the bushing 28 fitted therein extend downwardly to a pointbelow the lower extremity of the vertical bore 24 provided in the upperjaw H of the machine, the purpose of this construction being to afiordthe ram abearing surface of ,maximum extent as to reduce to a minimumthe portion of they ram which is unsupported against sidewise thrustduring the operation thereof. The bushing '28 is retained in position bya nut 29 threadedly engaging the upper end thereof and resting againstthe upper surface of the flange 28 of the sleeve 25, this 'nut 29 beingin turn secured in position against vertical displacement with respectto said flange 26 by means of an angular retainer 30 secured to theflange by circumferentially spaced bolts 3i. By loosening the said bolts3| and lifting the retainer 38 away from the flange 26, the nut 29 maybe rotated in one direc tion or another to .shift the bushing axially ofits .sleeve 25 in order to secure it in or remove it from its finalproper position vwithin the said sleeve. 'As appears most clearly inFigure 2, the

ram I9 is provided with an elongated vertical groove 32 in thecylindrical surface thereof for coaction with a key 33 fixed interiorlyof the bushing 28 to guide the ram and restrain it from angular movementrelatively to said bushing during vertical restriction of the ram.

Provided in the sleevetlt intermediate the upper and lower extremitiesthereof are a series of circumferentially spaced depressions or recesses34 for receiving the inner end of a spring pressed locking pin 35, thispin being adapted for projection into any one of the said recesses tolock 'the sleeve 25 against rotation within the bore 2d provided in theupper jaw H of the machine.

By so looking the said sleeve 25 in its adjusted desired position, itwill be apparent that the ram [9 will likewise be locked incorresponding position because the ram, while free to reciprocatevertically with respect to the sleeve 25, is lestrained from rotationrelatively thereto by means of the slot and key connection 32-33connecting it to the bushing 28, which latter in turn is nonrotatablyconnected to the sleeve 25 by the elements 29, 39 and 3!.

Depending from the arm ii of the machine is the lower extension 35 ofthe guide for the rotatable sleeve 25, it being observed that thisextension terminates just above the lower extremity of said sleeve 25and is provided with a plane cylindrical outer surface 3'! upon which isrotatably journalled a turret assembly, designated generally by thereference numeral 33. This turret assembly 38 essentially comprises anannular member 89 (see Figures 2, 3 and 4) of substantially L-shapedvertical cross-section, the bottom section 40 of which extends acrossand is disposed immediately beneath the lower extremity of the fixedguide extension 3%. Projected radially through the bottom section of theturret annulus 39 are a plurality of oircumferentially threaded into thesleeve 25 and the outer ends of which are provided with lock nuts 42 forretaining the pins securely in position. If desired and in someinstances it may be preferred, the pins 4| are threadedly secured in theturret member 35 and project radially therethrough with their inner endsmore or less loosely accommodated in recesses provided in the sleeve 25.By means of these radial pins it, the turret 38 is so related to thesleeve 25 that rotation of the turret effects rotation of the sleeve 25and the ram l9 through the intervention and by means of the parts abovedescribed.

In order to readily effect rotation of the turret as desired, it isprovided with a plurality of circumferentially spaced capstan handles43, these handles: being projected radially through the annular body '39of the turret with the inner ends 44 thereof seating in acircumferential groove 45 formed in the cylindrical outer surface of thefixed guide extension 38. The capstan handles 43 thus serve togetherwith the pins ii to retain the turret against vertical displacement withrespect to the fixed guide extension 35, yet free rotation of the turretrelatively to said extension is not impeded. Secured to the turret forrotation therewith are a pair of strippers it-55, each of which isprovided with means for vertically adjusting it axially of the turret,this adjusting spaced pins 53, the inner ends of which are' secureagainst chatter and vibration during the nibbling operation.

From the foregoing, it will be apparent that rotation of the ram [9about its axis may be readily efiected by angular adjustment of theturret through its capstan handles 43, the ram being held in itsangularly adjusted position by means of the spring pressed locking pin35, the inner end of which is adapted to seat in any one of the recesses3 3 provided in the sleeve 25. To change the angular position of theram, it is merely necessary to withdraw the locking pin 35 sufficientlyto permit free rotation of the sleeve 25 within the fixed guide bearingformedin the extremity of the arm H of the machine, this sleeve beingnon-rotatably associated with the turret through the intervention of theradial pins 4| and with the ram through the intervention of the bushing28 and the slot and key connection 3233 between the bushing and the ram.This latter slot and key connection, while preventing relative rotationbetween the ram and bushing, permits the ram to reciprocate verticallywithin the guide bushing and this is true regardless of the angularlyadjustedposition'of the ram.

One of the outstanding advantages of the construction just described isthat the bearing for the ram I9 is substantially coextensive in lengthwith the ram, thereby afiording a greater bracing for the ram againstsidewise thrust than has been possible of attainment heretofore.Moreover, the

arrangement not only permits the slot and key connection 32--33 to belocated at any point lengthwise of the bushing 28 but also permits ofthe use of a slot and key of such substantial length that better controlagainst torsional strains and stresses is obtained during verticalreciprocation of the ram. And finally, the arrangement provides aminimum of unsupported ram at the lower end thereof during operation ofthe machine, in consequence of which the tendency for the tool carriedby the ram to become misaligned with its fixed die, thereby resulting ininjury to both the tool and die, is for all practical purposes entirelyobviated.

To further support the tool against buckling and lateral stresses andstrains, the present invention contemplates the provision of a toolassembly of the character now to be described. As

appears most clearly in Figures 2 and 3, the ram 19 is axially boredthroughout its length, a relatively short intermediate section of thebore being of reduced diameter. The upper end of the ram bore isinteriorly threaded, as at 5!, for threaded engagement with the swivelstem 2i, while the lower end of the ram bore is provided with aninternal bearing surface 52 and an in ternally threaded section 53, thelatter being disposed between the bearing surface 52 and the mainsection 54 of the internal bore of the ram. An annular shoulder 55 isprovided at the upper extremity of the section 5d of the bore, thediameter of the latter being somewhat less than that of the bearingsurface 52.

Fitted within the section 54 of the ram bore and adapted to abut againstthe annular shoulder 55 aforesaid is a stripping sleeve 56 which isinteriorly threaded to adjustably receive an adjusting screw 5'1. Theupper end of this screw is squared or otherwise formed to provide atoolengaging head 57 while the lower end thereof is provided with asmooth cylindrical surface 58 for a purpose which. will be immediatelyapparent.

Fitted within the lower extremity of the ram. is an axially bored colletnut 58, the interme- The lower extremity of the collet nut bore istapered, as at 62, to provide a tapered seat for a collet 63, which maybe formed of twoor more separable segments or of one piece suitablysplit or notched to permit of its contraction when the collet nut 58 isthreaded into the ram.

Above its tapered lower section, the bore of the collet nut 58 iscylindrically smooth to accommodate a plurality of centrally aperturedspacers 86 arranged in stacked, coaxial relation. Projected through thealined apertures of the spacers and the bore of the collet 63 is thenibbling tool 65, the upper end of which abuts against the adjustingscrew 51. And fitted to the upper end of the tool is a removably fixedcollar 66 which is disposed within therarn. In other words, the spacers64 and 56 conjointly provide a continuous support for the entire lengthof the 'tool 65 except for the relatively short portion thereof whichpierces the work and, therefore, necessarily projects unsupported belowthe lower extremity of the ram.

As the tool wears shorter and it becomes necessary to adjust it axiallydownward of the ram (which adjustment is accomplished by means of theadjusting screw 51) as many of the spacers as may be necessary areremoved and the adjusting screw 5'! is projected into the bore of thecollet nut to an extent sufiicient to compensate for the drop in toolposition occasioned by the removal of the spacers 64. It will beobserved that in all positions of tool adjustment the upper end of thetool is constantly in abutting relation to the lower end of theadjusting screw so that at no time is there any slack or play betweenthe tool and ram during the downward or working stroke of the latter,the downward thrust being imparted by the ram to the tool as follows:

ram shoulder 55 to stripping sleeve 56 to adjusting screw 51 and finallyto tool 65. Neither is there any slack or play between the tool and ramon the upward or stripping stroke of the latter because in this strokethe load is transmitted from the tool to its fixed sleeve 66, thence tothe collet nut and finally to the ram.

Preferably, the adjusting screw 51 is provided with threads of reversedirection and different pitch from the threads on the collet nut 58 toobviate the possibility of the adjusting screw backing out and away fromthe tool during the operationof tightening the collet nut in the ram.

From the foregoing description of the tool holder assembly, whichincludes the lower part of the ram and the internal parts thereofimmediately associated therewith, it will be apparent that thearrangement provides very-accurate centering of the tool and at the sametime provides such full and complete (bracing thereof that any tendencyfor the ,tool to buckle or spring out of line with the die is entirelyobviated. In addition, the assembly .provides for easy and readyadjustment of the tool axially of the ram to compensate for Wear of thetool occasioned by normal use thereof and it also facilitates theremoval of the tool from the ram whenever required. It will be observedthat in the construction shown more particularly in Figure 3, in orderto effect adjustment of the adjusting screw 51 axially of the ram it ismerely necessary to remove the collet nut 58 so as to permit the toolholder assembly, including the sleeve 56 and screw 51, to ,be withdrawnfrom the ram bore whenever the screw may be adjusted axially of itssleeve 56. In other words, the adjustment of the adjusting screw isaccomplished .by'operating upon the upper end thereof.

Figure 6 shows a modified form of tool holder assembly wherein provisionis made for effecting adjustment of the adjusting :screw it bymanipulating the lower end thereof and so obviating the necessity ofremoving the ram from the machine. In this modified arrangement, theadjusting screw 70 is threaded into the intermediate section H of theram and the lower extremity thereof is provided'with a tool engagingextremity 12. Inasmuch as this latter extremity of the adjusting screwdirectly abuts the upper end of the tool, exactly as in the constructionshown in Figure '3, it will be apparent that the downward or workingthrust of the ram is imparted directly to the adjusting screw 10 and bythe latter to the tool. The arrangement of Figure 6 thus eliminates thenecessity of employing a threaded sleeve such as that designated 56 inFigure 3. Also, it will be observed that in the modified arrange- .mentthe collet nut 13 is not of the same length .as that shown in Figure 3but instead it cooperates with an additional separate sleeve member .14to accomplish the same results as are accomplishedxby the relativelylongcollet nut 58 of Fig- :ure 3. In all other respects, the arrangement:shown in Figure 6 is similar structurally and functionally to thatpreviously described.

The invention is susceptible of various changes and modifications whichmay be made from time to time without departing from the real spirit :orgeneral principles thereof and it is intended, therefore, to claim thesame broadly, as well as specifically, in accordance with the appendedclaims.

What is claimed as new and useful is:

1. In a cutting machine, a frame having upper and lower arms, the upperof said arms being provided in its forward extremity with a guide-menibervhaving cylindrical 'bore, the axis of which bore extendsvertically, a sleeve rotatably journallediin said guide bore, a ramdisposed interiorly of said sleeve and arranged for verticalreciprocation relatively thereto, and means disposed exteriorly .of andjournalled upon the external surface of said guide member for rotatingsaid :sleeve.

2. In a cutting machine, a frame having upper and'lower arms, one ofsaid arms being provided with a guide having a vertically disposedcylindrical bore, a sleeve rotatably journalled in said guide bore, aram disposed interiorly of said sleeve, means providing for verticalmovement of saidram relatively to said sleeve while preventing relativerotation therebetween, and means dis- 'posed exterior-1y of andjournalled upon the external surface of said guide for commonly rotatingsaid sleeve and ram, said "last-mentioned means being provided with:circumferentially spaced radially extending operating handles.

' 3. In a cutting machine, a frame having upper and lower arms, one ofsaid arms being provided with a fixed die, and the other of said armsbeing provided with a guide having a cylindrical bore disposed coaxiallywith respect to said die, a sleeve rotatably journalled in said guidebore, a ram disposed interiorly of said sleeve, said ram beingvertically reciprocable but non-rotatable with respect to said sleeve,and a turret journalled upon the external surface of said guide andconnected to said sleeve for eifecting rotation of the latter within itsjournalling sleeve.

4. In a cutting machine, a frame having upper and lower arms, one ofsaidarms being provided with a fixed die, and the other of said armsbeing provided with a guide having a cylindrical bore disposed coaxiallywith respect to'saiddie, asleeve rotatably journalled in said guidebore, a ram disposed interiorly of ,saidsleeve, said ram beingvertically reciprocable but non-rotatable with respect to said sleeve,and a turret journalled upon the external surface :of said guide andconnected to said sleeve for effecting rotation of the latter within itsjournalling sleeve, the connection between said turret and sleeve beingdisposed buneath the lower extremityof said guide bore.

5. In a cutting 'machine, means providing a vertically disposedcylindrical guide bore and a coaxial outer cylindrical bearing surface,asleeve rotatably journalled within said guide bore, a ram disposedinteriorly of said sleeve for reciprocation relatively to and rotationwith said sleeve, said guide bore and sleeve being extended downwardlyto a point closely adjacent the lower extremity of said ram whereby toprovide the latter with maximum bearing surface during both working andnon-working strokes thereof, and means journalled upon said bearingsurface for commonly rotating the sleeve and ram.

6. In a cutting machine, means providing a vertically disposedcylindrical guide bore and a coaxial outer cylindrical bearing surface,a sleeve rotatably journalled within said guide bore, a ram disposedinteriorly of said sleeve for reciprocation relatively to and rotationwith said sleeve, said guide bore and sleeve being extended downwardlyto a point closely adjacent the lower extremity of said ram whereby toprovide the latter with maximum bearing surface during both working andnon-working strokes thereof, and a turret journalled upon said bearingsurface for commonly rotating said sleeve and ram, said turret andsleeve being connected together at a point disposed beneath said guidebore.

7. In a cutting machine, means providing a vertically disposedcylindrical guide bore and a coaxial outer cylindrical bearing surface,said bearing surface encompassing the lower portion of. said guide bore,a sleeve rotatably journalled within said guide bore, a turretjournalled upon said bearing surface and having means projectingradially beneath the lower end of said bearing surface for affording aconnection between said turret and said sleeve, and a ram disposedinteriorly of said sleeve and adapted for vertical reciprocationrelatively thereto.

8. In a cutting machine, means providing a vertically disposedcylindrical guide bore and a coaxial outer cylindrical bearing surface,said bearing surface encompassing the lower portion of said guide bore,asleeve rotatably fitted within and extending the full length of saidguide bore, a bushing non-rotatably fitted within said sleeve, avertically reciprocable ram fitted within said bushing, and meansjournalled upon said bearing surface and connected to said sleeve forangularly adjusting said sleeve about its central vertical axis.

9. In a cutting machine, means providing a vertically disposedcylindrical guide bore and a coaxial outer cylindrical bearing surface,said bearing surface encompassing the lower portion of said guide bore,a sleeve rotatably fitted within and extending the full length of saidguide bore, a bushing non-rotatably fitted within said sleeve, avertically reciprocable ram fitted within said bushing, means journalledupon saidbearing surface and connected to said sleeve for angularlyadjusting said sleeve about its central vertical axis, and a slidablekey connection between said ram and bushing to permit said verticalreciprocation of the ram relatively to said sleeve at the same timepreventing relative rotation therebetween.

10. In a cutting machine, a tool holder including a ram having an axialbore, an annular shoulder formed within said bore, an interiorlythreaded sleeve disposed within said bore in abutting relation to saidshoulder, a threaded screw fitted in said sleeve axially adjustable withrespect thereto,' a tool disposed interiorly of the ram bore in coaxialalignment with said threaded screw and with its upper end abutting thelower end of said screw, and means clamped within the bore of said rambelow said sleeve and in embracing relation with respect to said tool tosecure the latter in position and restrain it against buckling, saidmeans including a plurality of removable spacing elements adapted to bearranged in stacked embracing relation with respect to said tool and oneor more of which may be removed as said threaded stem is axiallyadjusted to compensate for shortened length of the tool.

11. In a cutting machine of the reciprocatory type, a ram constructionhaving a bore, a tool in the bore having a collar removably secured tothe upper end thereof, axially adjustable means for transmitting thrustfrom the ram construction directly to the upper end of the tool, colletmechanism carried by the lower end of the ram construction for grippingand centering the lower end of the too], said collet mechanismincludingan elongated axially bored bushing threadedly received with inthe lower end of said ram construction, and a plurality of centrallyapertured spacer discs disposed within the bore of said bushing andfitted over the shank of said tool to resist buckling of the latter.

12. In a cutting machine of the reciprocatory type, a ram constructionhaving a bore, a tool in the bore having a collar removably secured tothe upper end thereof, axially adjustable means for transmitting thrustfrom the ram construction directly to the upper end of the tool, colletmechanism carried by the lower end of the ram construction for grippingand centering the lower end of the tool, said collet mechanism includinging and fitted over the shank of said tool to resist buckling of thelatter, one or more of said spacer discs being removable from within thebore of said bushing to permit axial adjustment of the tool downwardly.

13. In a cutting machine of the character defined in claim 1.2 whereinthe thrust transmitting means is in the form of a threaded screw thelower end of which is adapted for projection into the bore of saidbushing to a greater or less extent depending upon the number of spacerdiscs removed from said bushing.

14. In a cutting machine of the reciprocatory type, a ram constructionhaving a bore, the lower section of said bore having vertically spacedcylindrical surfaces of different diameters, said surfaces beingseparated by a threaded section, bushing means adapted to be fitted intosaid lower section of the ram and having vertically spaced externalcylindrical surfaces and an intermediate threaded section forrespectively engaging the complementally formed surfaces and threadedsection in the ram construction bore to insure coaxial centering of thebushing means within the ram construction, a tool disposed interiorly ofsaid bushing means andhaving a collar secured to the upper end thereof,said collar being snugly fitted within the bore of said bushing means,collet mechanism carried by the lower end of said bushing for grippingand centering the lower end of the tool, and spacing means fitting thebore of said bushing means between said collar and said collet mechanismand surrounding the tool shank to resist buckling of the latter.

15. In a cutting machine of the reciprocatory type, a ram constructionhaving a bore, the lower section of said bore having vertically spacedcylin drical surfaces of different diameters, said surfaces beingseparated by a threaded section, bushing means adapted to be fitted intosaid lower section of the ram and having vertically spaced externalcylindrical surfaces and an intermediate threaded section forrespectively engaging the complementally formed surfaces and threadedsection in the ram construction bore to insure coaxial centering of thebushing means within the ram construction, a tool disposed interiorly ofsaid bushing means and having a collar secured to the upper end thereof,said collar being snugly fitted within the bore of said bushing means,collet mechanism carried by the lower end of said bushing for grippingand centering the lower end of the tool, spacing means fitting the boreof said bushing means between said collar and said collet mechanism andsurrounding the tool shank to resist buckling of the latter, and meansfor transmitting thrust from the ram to the upper end of the tool andfor providing adjustment of the tool axially of the bore.

16. In a'cutting machine of the character defined in claim 15 whereinsaid thrust transmitting means is in the form of a threaded screw, theupper end of which is fashioned to take an adjusting tool.

17. In a cutting machine of the character defined in claim 15 whereinsaid thrust transmitting means is in the form of a threaded screw, thelower end of which is fashioned to take an adjusting tool.

18. In a cutting machine of the character defined in claim 15 whereinsaid thrust transmitting means is in the form of a threaded screw, oneextremity of which is fashioned to take an adjusting tool.

CHARLES B. GRAY.

